In order to enhance or modify the chemical and/or physical characteristics of certain pesticides, certain materials are added to form a mixture for spraying. Generally referred to as adjuvants, these materials have no pesticidal activity of their own. Since spray application can be critical to the performance of the agricultural chemical, adjuvants are added to reduce application problems such as chemical stability, incompatibility, solubility, suspension, foaming, drift, evaporation, volatilization, phytotoxicity, surface tension, droplet size and coverage. They can, depending on their type, enhance wetting, spreading, sticking, emulsifying, dispersing and biological activity. Adjuvants include wetting agents, crop oil concentrates, spreaders, stickers, buffering agents, foaming and anti-foaming agents, dispersing agents and drift control agents.
Over 200 EPA-registered pesticides have specific recommendations on their labels for adjuvant use. These are recommended for one of two reasons. The first reason is to enhance biological activity of the pesticide. The second reason would be to reduce, minimize or eliminate spray application problems as noted previously. There are several different types of adjuvants recommended. To achieve consistent, effective results from them, the user must first select the desired type of adjuvant and then the appropriate product within that specific type for use with a particular pesticide and then use that product at recommended rates.
Many pesticide labels require or recommend the use of a "spreader-sticker" with the use of the pesticide. The American Society of Testing and Materials defines spray adjuvant terminology in their document E1519-94a which is incorporated by reference in its entirety. This organization has defined a spreader as "a material which increases the area that a droplet of a given spray mixture will cover on a target." A sticker is defined as "a material that assists the spray deposit to adhere or stick to the target and may be measured in terms of resistance to time, wind, water, mechanical action, or chemical action." A spreader-sticker is defined as "a material that has the properties of both a spreader and a sticker".
Historically, many materials have been used as stickers in pesticide-based spray mixtures. A polymer of Beta-pinene is currently marketed by Helena Chemical Company and by Miller. A latex-based resin has been marketed by United Agri-Products and others. Several resins have been used as sticking agents. Free fatty acids have been also been used as stickers. U.S. Pat. No. 5,543,384 describes a method of making a sticker-extender for pesticides comprising a first mixture containing an anhydride, an acid and turpentine mixed with a second mixture containing an isomeric alcohol and at least one amino alcohol. All of these products are essentially hydrophobic film-formers and require the use of emulsifiers or co-surfactants to disperse them in water for the initial application. The surfactants used for emulsifying or dispersing the stickers are generally what is relied upon for the spreader functionality of these products.
Historically, these products have not provided significant spreading if they do indeed actually enhance sticking, or they do not provide significant sticking if they do indeed actually enhance spreading. It would be advantageous to combine both of these functions effectively into one single product. This would provide ease of use for the consumer.
The beta-pinene based products have historically caused mixing problems with some pesticides. Specifically, dry flowable or wettable powder formulations, can interact with beta-pinene emulsions and cause severe tank mixing problems. Beta-pinene, latex, and free fatty acids can also leave undesirable films in spray tanks which cause clean-out problems for pesticide applicators.
Latex-based stickers have provided excellent sticking capabilities, but have formed water-impermeable films on plant surfaces. This film does not allow contact between pest and pesticide, which is essential for contact pesticides.
U.S. Pat. Nos. 5,178,795; 5,393,791 and 5,580,567 are all issued to Johnnie R. Roberts which are all incorporated herein. These patents describe a homogenous non-aqueous adjuvant composition comprising a spray oil and surfactant blend with an acidic pH of less than about 7. In addition, these patents require an oil or its equivalent. However, contrary to the Roberts' patents, the applicants have found that the novel spreader-sticker surfactant combination works without an oil or its equivalent being required and best in the basic range having a pH of greater than about 7 and preferably at least about 8. The adjuvants described in all three Roberts patents are excluded from this invention and the claimed invention.
Alkanolamide surfactants have not been used frequently in agriculture. These surfactants have been used for a number of years as thickeners in the personal care industry. Alkanolamides have also been widely used as foam stabilizers in the laundry and detergent industry.
U.S. Pat. No. 5,622,911 which is incorporated by reference in its entirety, describes a method for enhancing the efficacy of agricultural chemical with alkoxylated fatty acid amides. The fatty acid acids correspond to R.sup.1. The fatty acid amides must be alkoxylated with ethoxy {(CH.sub.2 R.sup.2 or 3 CHO) having R.sup.2 or 3 as hydrogen} or isopropoxy {(CH.sub.2 or 3 CHO) having R.sup.2 or 3 as methyl}. We have found an agricultural product that is not alkoxylated and a method of making an agricultural product without alkoxylation being required.
It is the object of this invention to provide an effective sticker in combination with an effective spreader in a single phase adjuvant composition or in a single phase pesticide composition. These formulations do not leave residues in spray tanks which give applicators clean-out problems. Alkanolamide spreader stickers have not caused any mixing problems with dry pesticide tank mixes.